反应详情

To a solution of [2-methyl-4-(5,6,7,8-tetrahydronaphthalen-2-yl)-5-oxazolyl]carboxylic acid (6.0 g) in methanol (120 mL) was added conc. sulfuric acid (6.0 mL) and the mixture was stirred with heating under reflux for 18 hrs. The reaction mixture was concentrated and the residue was diluted with water. The mixture was extracted with ethyl acetate. The organic layer was washed successively with saturated aqueous sodium hydrogen carbonate, water and saturated brine, dried over anhydrous magnesium sulfate, and concentrated to give methyl [2-methyl-4-(5,6,7,8-tetrahydronaphthalen-2-yl)-5-oxazolyl]carboxylate (4.75 g, yield 76%) as crystals. Recrystallization from ethanol gave colorless crystals. melting point: 96–97° C.

1. temperaturewith heating
2. temperatureunder reflux for 18 hrs
3. concentrationThe reaction mixture was concentrated
4. additionthe residue was diluted with water
5. extractionThe mixture was extracted with ethyl acetate
6. washThe organic layer was washed successively with saturated aqueous sodium hydrogen carbonate, water and saturated brine
7. dry with materialdried over anhydrous magnesium sulfate
8. concentrationconcentrated